The overnight ban for parking on main streets starts December 1, and is in effect from 3 am to 7 am, regardless of snow or the snow forecast. The ban stays in effect until April 1.
If you live in the city or get there frequently, you need to listen to your City Mom and subscribe to Notify Chicago , because they send out email alerts concerning all sorts of good-to-know stuff, like when streets will be closed or congested because of the circus or a concert or race, etc. Just a public service announcement. You're welcome. And don't come crying to me if you get a ticket, or worse, towed, or even worse than that--you end up late to your manicure.